Fastening means having undulating substructure-engaging surface



M. UIN-ro 3,053,300 FASTENING MEA HAVING UNDULATING SUBSTRUCTURE-ENGAGING FACE Filed June 26, 1

sept. 11, 1962 United States Patent O 3,053,300 FASTENING MEANS HAVING UNDULATNG SUBSTRUCTURE-ENGAGiNG SURFACE Mario Quinto, Revere, Mass. (3i-19 35th St., Astoria, NX.) Filed June 26, 1957, Ser. No. 668,087 2 Claims. (Cl. ISI-41.72)

This invention relates to fastening means for use in connection with sheet metal. More particularly, it provides improved anchor nuts, anchor studs, and the like, which may be used without producing undue stresses in the sheet metal.

One object `of the present invention is to provide for mounting anchor nuts, anchor studs and the like in holes drilled through sheet metal in such a manner as to eliminate the possibility of rotation relative to the sheet metal. while at the same time avoiding uneven stressing of the sheet metal at particular points or along particular lines.

Another object is to provide a fastening means of the character referred to which is not dependent on frictional contact with the sheet metal on which it is mounted for torsional rigidity.

Still another object is to provide such a fastening means Which gives strengthening reinforcement of the sheet metal around the entire 360 of the hole drilled therethrough.

Other objects are to provide such a fastening means which can be mounted in the sheet metal through holes of standard size, which can be removed and replaced without damage to the sheet metal, which can be mounted in metal sheets of varying thickness using the same mounting tools, which can be mounted so as to be flush with one side ofthe sheet metal, and which can be easily and rapidly mounted in the sheet metal without rotational orientation with respect thereto during assembly.

Other objects, advantages and -features will appear from the following description of preferred embodiments of the invention, taken together with the drawings thereof, in which:

IFIG. l is an isometric view of a preferred embodiment of an anchor nut according to the invention;

FIG. 2 is a plan view thereof;

FIG. 3 is a 90 sectional view taken at 3-3 of FIG. 2;

FIG. 4 is an exploded, partially sectional, partially broken away view of said anchor nut in association with a piece of sheet metal having a hole therein;

FIG. 5 shows said preferred anchor nut assembled to said sheet metal, and :another piece of sheet metal held thereagainst by a bolt;

FIG. 6 is a developed sectional view showing undulations in the sheet metal and anchor nut, around the particular circumference at 6--6 in PIG. 5; and

FIG. 7 is a modified embodiment of `an anchor nut according to the invention.

Referring now to the drawing, there is shown in lFIG. l an anchor -nut indicated generally at 10, which includes an annular body 12, a projecting annular shank 14- integral therewith, and an annular sheet metal engaging surface 16 disposed around the shank 14. There is also a small planar sheet metal engaging surface 1S around the outside diameter of the annular body 12. A threaded hole 20 extends through the device.

As -shown more particularly in lFIG. 3, the surface 16 defines a depression extending around the annular shank. The surface 16 has a smoothly undulating configuration, shown in detail for one particular circumference therearound in FIG. 6, so that the depth of the depression defined by surface 16 varies at different points, not only on different circumferences around said surface, but also at different points along particular individual circumferences therearound. The undulations proceed in gentle curvature, so that when sheet metal around a hole therethrough 3,053,300 Patented Sept. 11, 1962 ice is deformed to conform to surface 16, and held thereagainst by deforming the extremity 22 of the annular shank 14 thereover, there will be no particular points or lines in the sheet metal at which -any increased stress is set up. `yOn the contrary, stress in the sheet metal will be substantially the same throughout the 360 perimeter of the hole, and thus cause no tendency to failure. The depression defined by surface 16 is generally deepest adjacent the annular shank 14, and becomes shallower as it approaches 'the surface 18. Because the surface -18 is in a single plane, at its outer diameter the surface 16 does not undulate and has no depth. At the inner diameter of the surface 16, however, adjacent the annular shank 14, undulation is between its maximum extremes (as more particularly shown in FIG. 3). There are two complete undulations around inner diameter of the surface 16, depth of the depression being deepest at two points 180 apart, and shallowest (on said inner diameter) at two points each of which are away from the firstmentioned two points. Between adjacent points (of each of said four points) the inside diameter is characterized by general gentle curvature up and down.

As will be noted, thus, in this preferred embodiment the surface 16 is defined by a multiplicity of lines all of which pass through a circle which defines the outside diameter of the depression 16 (and the inside diameter of the surface '18), which lines, because of the abovedescribed depth variations at the inside diameter of the surface 16', define varying angles with the axis of the annular body 12.

In mounting the anchor nut on a piece of sheet metal 30, a hole 32 of standard size (which would vary of course depending on the size of Ithe anchor nut required) is drilled, and the annular shank 14, which slidably ts the same, is passed therethrough. Thereupon, a mounting tool is used to deform the extremity Z2 of the annular shank 1'4 over the periphery of the hole 32. This deforming step forces the lower surface of the periphery of said hole to conform to the undulating surface 16, and since the sheet 30 is of a uniform thickness, its opposite surface, as well as the lower surface 36 formed in said anchor nut by said deforming, is given lan undulating conguration corresponding to that of surface 16, but parallel thereto and spaced therefrom an amount corresponding to the thickness of the sheet metal.

In the above manner the sheet metal is gripped securely by the anchor nut 10. Because of the undulating form given the sheet metal and the anchor nut portions gripping it, relative rotation between the nut `and sheet metal is prevented without reference -to `frictional forces. At the same time, by virtue of the gentle curvature taken by the undulation, there are no lines or points in the periphery of the hole at which increased stresses `are set up in the sheet metal. Accordingly, a very strong joint is achieved, which not onl-y Iavoids weakening the metal, but which by virtue of reinforcing the same around 360 with substantially uniform stresses, actually reinforces the sheet metal.

As also shown in FIG. 5, one surface 33 of the anchor nut may be made substantially coplanar with one surface 40 of the sheet metal, which is anadvantage.

Inasmuch `as the depth of the surface toward which the shank extrem-ity 22 must be deformed varies, it is in some cases desirable -to make the annular shank of varying axial lengths, around the periphery thereof (either by scooping out `certain portions thereof, las shown in the modification of FIG. 7, `or by extending certain portions thereof, as in convex arcs), so that after deforming the extremity thereof the surface 38 is substantially coplanar throughout the same.

It will be apparent that more or less than one complete undulation around the diameter of the sheet metal engaging surface may be provided. Or one or more asymmetrical undulation may be provided therein, so long as curvature is kept gentle to avoid production of any lines or points of increased stress in the sheet metal. be apparent also, that the undulating surface may be provided on a washer not integral with the annular shank, so long as the two are operatively `secured together as for example by a head integral with the shank and backing up the washer. Other variations within the spirit and scope of the invention will appear to those skilled in the art.

-I claim:

1. Fastening means secured to sheet metal characterized by a hole therethrough which comprises an `annular body with an annular shank having a free end projecting therefrom and through said hole and an annular sheet-metalengaging surface on said body and around said annular shank, said surface being of smoothly undulating character to define 'a depression around said shank varying in depth from generally deepest toward said shank to shallowest toward the outside diameter of said annular body and characterized by gentle curvature throughout the lsame providing varying depths in said depression along each of particular individual circumferences therearound, said surface being defined by a multiplicity of straight lines delining varying angles with the axis of said annular body, all of said lines intersecting a circular line defining the outside circumference of `said depression and diverging from said axis in a direction toward said shank free end, the variation in depth in said depression along particular individual circumferences therearound diminishing toward the outside diameter of said depression, and the extremity `of said annular shank being deformed over and against said sheet metal around said hole into configuration corresponding to said depression and parallel to said surface thereof, whereby said sheet metal is deformed -around said hole so .as to conform to said depression and is secured between and in engagement with said surface and said shank conguration.

2. The fastening means of claim 1 in which said depression is deepest at two points on the ins-ide circumference thereof and 180 `apart and is shallowest `at two points on the inside circumference thereof and each 90 away from each of said first-mentioned two points, and in which said inside circumference is characterized by gentle vertical curvature from each of said points to the adjacent said points.

References Cited in the tile of this patent UNITED STATES PATENTS Re. 15,413 Reynolds July 18, 1922 342,225 Roberts May 18, 1886 796,671 Palmer Aug. 8, 1905 1,484,469 Brucelaire Feb. 19, 1924 1,759,339 Andrew May 20, 1930 2,447,536 Robinson Aug. 24, 1948 2,619,146 Poupitch May 25, 1952 2,788,232 Stadthaus Apr. 9, 1957 

